Men who develop male pattern baldness by age 30 have a lower risk of developing prostate cancer, according to a study conducted by Public Health Sciences Division researchers. The findings, which involved nearly 2,000 men, were published March 3 in the online edition of Cancer Epidemiology.
Dr. Jonathan Wright and colleagues analyzed 35- to 76-year-old King County residents (about half were prostate cancer cases) and found those who began losing their hair by age 30 had a 29 percent reduction in the risk of developing prostate cancer. Men who had been balding longer experienced a 45 percent risk reduction. The protective effect was found for both aggressive and less-aggressive forms of the disease.
“We were interested in these conditions since both are common, age-associated, heritable and related to androgens,” said Wright, who is also an assistant professor in the University of Washington School of Medicine’s Department of Urology. “These findings are in contrast to the small number of previous studies; however, in most of those studies, hair pattern was assessed at time of diagnosis or study enrollment. As a result, most men were over 55, whereas we use reported hair pattern at age 30. Early onset baldness may be a more relevant measure considering the long latency of prostate cancer and the presumed related effects of the androgen pathway in these conditions.”
The exact link between baldness and prostate cancer is unknown. Wright suspects a genetic variant in the male hormone receptor gene may affect both conditions. Early hair loss in men is usually due to excessive exposure of dihydrotestosterone, a chemical produced from testosterone that causes the hair follicles to shrink and become thinner. Testosterone levels affect both male pattern baldness and prostate cancer. Male pattern baldness affects about 25 percent of men by age 30 and about half of men by age 50.
Wright said if the findings are confirmed by further research, early onset baldness may be an easy way to determine which men are at lower risk for future development of prostate cancer.
The National Institutes of Health funded the study, with collaboration from PHS researchers Drs. Daniel Lin and Janet Stanford, as well as Dr. Stephanie Page, UW School of Medicine Department of Medicine.